Vehicles often include a climate control system for maintaining an interior climate of an occupant compartment of the vehicles. Air handling for the climate control system may be provided by a heating, ventilation and air conditioning (HVAC) assembly. The HVAC assembly includes a network of ducts and vents for transferring a flow of air through and out of the vehicles. The airflow in the occupant compartment can enhance occupant comfort, provide for defogging of windows as well as other features. The transfer of fresh air into the occupant compartment and of stale air out of the occupant compartment is typically accomplished via an interconnected system of air vents and air ducts. The air duct openings are positioned in various locations in the occupant compartment, such as in the instrument panel, a pillar, a quarter panel, or the like.
Air ducts may be provided for the controlled flow of air into the occupant compartment of the vehicle and for the controlled flow of air out of the occupant compartment of the vehicle. The air ducts may have other functions as well, and may be part of an integrated air duct assembly. Various considerations influence the configuration of the air ducts. For example, one consideration may be to maintain an effective transfer of airflow both in and out of the vehicle for operation of the HVAC system. Yet another example may be whether an air duct is load-bearing. Such load-bearing air ducts may be formed using a relatively hard plastic material to withstand loads, such as a high-density polyethylene. However, such hard plastic materials may have limited insulating and noise reduction properties. There continues to be a need for air systems that can be used to improve HVAC performance.